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Review Article

Lasers in dermatology : Four decades of progress
Ahad SMMA, Chowdhury MR
The ORION Medical Journal 2009 Jan;32(1):636-638

Summary
Advances in laser technology have progressed
so rapidly during the past decade that
successful treatment of many cutaneous
concerns and congenital defects, including
vascular and pigmented lesions, tattoos, scars
and unwanted hair- can be achieved. The
demand for laser surgery has increased as a
result of the relative ease with low incidence
of adverse postoperative sequelae. In this
review, the currently available laser systems
with cutaneous applications are outlined to
identify the various types of dermatologic
lasers available, to list their clinical
indications and to understand the possible
side effects.
Abbreviations used
APTD :
CO2 :
CW
:
Er:YAG:
FDA :
IPL
:
KTP :
LP
:
Nd
:
PDL :
PDT :
QS
:
YAG :

Argon-pumped tunable dye
Carbon dioxide
Continuous wave
Erbium:YAG
Food and Drug Administration
Intense pulsed light
Potassium titanyl phosphate
Long-pulsed
Neodymium
Pulsed dye laser
Photodynamic therapy
Quality-switched
Yttrium-aluminum-garnet

Laser history
The term laser is an acronym for light
amplification by the stimulated emission of
radiation. The first laser was developed by
Maiman1 in 1959 using a ruby crystal. The
concept of stimulated light emission was
initially introduced by Einstein2 in 1917. In
1963, Dr. Leon Goldman pioneered the use of
lasers for cutaneous applications by
promoting
laser Muhammad
for variousAli
cutaneous
1. Dr. Syedruby
Mamoon
Ahad,
3-5
pathologies.
The
development
of
theand
argon
MBBS, DDV, MD, nAssosicate Professor
&Head,
CWDepartment
carbon dioxide
(CO2)
lasers
of Dermatology, SOMC&Hsoon
email: [email protected]
followed
and served as the focus of cutaneous
6
2. Dr.
Matiurduring
Rahman
, MBBS
laser
research
theChowdhury
next 2 decades.
DDV Student, Department of Dermatology,
SOMC&H

The ORION. Vol 32, Issue 1, January 2009

Cutaneous laser surgery was revolutionized in
the 1980s with the introduction of the theory
of selective photothermolysis by Anderson
and Parrish.12 During the past decade
extensive advances in laser technology have
refined cutaneous laser surgery to the point
that it is now considered a first line treatment
for many congenital and acquired cutaneous
conditions.
Laser principles
The therapeutic action of laser energy is based
on the unique properties of laser light itself
and complex laser-tissue interactions.13-15 At
certain wavelengths of light, specific
absorption of laser energy can be achieved by
distinct cutaneous targets. Laser light can be
focused into small spot sizes allowing precise
tissue destruction. When a laser is used on the
skin, the light may be absorbed, reflected,
transmitted or scattered. Once laser energy is
absorbed in the skin 3 basic effects are
possible: photothermal, photochemical or
photomechanical effects. The depth of
penetration of laser energy into the skin is
dependent upon absorption and scattering.
Scattering is minimal in the epidermis and
greater in the dermis. In general, the depth of
penetration of laser energy increases with
wavelength. Therefore, on the basis of these
principles, laser parameters (wavelength,
pulse duration, and fluence) can be tailored
for specific cutaneous applications to effect
maximal target destruction with minimal
collateral thermal damage. Because cutaneous
lasers have different clinical applications
related to their specific wavelengths and pulse
duration, the choice of laser should be on the
basis
of
the
individual
absorption
characteristics of the target chromophore.17, 18
Vascular-specific lasers
Vascular-specific laser systems target
intravascular oxyhemoglobin to effect
destruction of various congenital and acquired
vascular lesions. Lasers that have been used
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Review Article
to treat vascular lesions include: Argon (488514 nm), APTD (577 and 585 nm), KTP (532
nm),
Krypton
(568
nm),
Copper
vapor/bromide (578 nm), PDL (585-595 nm),
Nd:YAG (532 and 1064 nm).
The flashlamp-pumped PDL was the first
laser specifically developed for treatment of
vascular lesions based on the principles of
selective photothermolysis.12 The PDL has
revolutionized the treatment of many vascular
lesions and is considered the laser of choice
for most benign congenital and acquired
vascular lesions because of its superior
clinical efficacy and low risk profile.17 This
laser has been used to successfully treat a
variety of vascular lesions such as port-wine
stains, facial telangiectases, hemangiomas,
pyogenic granulomas, Kaposi's sarcoma and
poikiloderma of Civatte .18,19

PDL with longer wavelengths (585, 590, 595
and 600 nm) and extended pulse duration
have been developed to effect relatively deep
tissue penetration.
Laser treatment for hypertrophic scars,
keloids
Hypertrophic scars and keloids develop as an
abnormal response to cutaneous injury and
are characterized by an over abundance of
collagen. These types of scars are notoriously
difficult to eradicate and have a high rate of
recurrence after traditional treatments
including surgical excision, dermabrasion,
radiation and intralesional therapy.20,21
Progress in laser technology and refinements
in technique have made laser therapy one of
the most advantageous modalities for the
treatment of hypertrophic scars and keloids.
In 1995, Alster and Williams performed the
first controlled study of the response of
hypertrophic scars and keloids to the PDL on
median sternotomy scars.

Figure 1: Port-wine stain in infant before treatet(A) and
resolution after 8,585-nm pulsed dye laser treatment(B)

Figure 4: Hypertropic facial scars before (A) and after (B)
improved scar color, height, and plability after two 585-nm
pulsed dye laser treatments

Figure 2: Facial telangiectases before(A)and after (B)
improvement with 2 pulsed dye laser treatment

Figure 6: Multicolored professional tatto before (A) and after
(B) lesional clearance after 9 treatments with quality
switched 755-nm alexandrite laser (blue/black inks) and 4
treatments with frequency-doubled 532-nm
neodymium:yttrium-aluminum- garner laser (yellow/red inks)
Figure 3: (A)Poikiloderma on neck and chest before
treatment. (B)Improvement seen after series of imtense
pulsed light treatments.

The ORION. Vol 32, Issue 1, January 2009

Lasers use for the treatment of hypertrophic
scars and keloid are CW Lasers (CO2, 1argon,
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Review Article
Nd:YAG) and PDL. The PDL has become a
first line treatment for hypertrophic scars and
keloids.
Pigment-specific lasers
Melanin-specific, high-energy, QS laser
systems can successfully lighten or eradicate
a variety of benign epidermal and dermal
pigmented lesions and tattoos with minimal
risk of untoward effects. Epidermal lesions
(solar lentigines, ephelides, cafe´-au-lait
macules, and seborrheic keratoses); dermal
and
mixed
epidermal/dermal
lesions
(melanocytic nevi, blue nevi, nevi of Ota/Ito,
infraorbital hyperpigmentation, drug-induced
hyperpigmentation, Becker's nevi, and nevus
spilus); and amateur, professional, and
traumatic tattoos have all been shown to be
amenable to laser treatment.22 Laser systems
used for eradication of benign pigmented
lesions and tattoos have included not only
CW and quasi-CW lasers (argon, CO2,
copper vapor, krypton, KTP). But also the
510-nm PDL and various QS systems (532and 1064-nm Nd:YAG, 694-nm ruby, 755-nm
alexandrite). LP laser systems (ruby,
alexandrite, 810-nm diode, and 1064-nm
Nd:YAG) have also been used to better target
some dermal pigmented lesions.
Photoepilation
Excessive hair growth in cosmetically
undesirable locations may be the result of a
variety of factors, ranging from hereditable
causes and endocrine disease to exogenous
drug therapy. Until recently, electrolysis was
the only method for long-lasting hair removal;
however, it is associated with as much as 50%
hair regrowth and the potential for scarring
and dyspigmentation.23, 24 Laser systems and
IPL sources currently approved by the FDA
for the reduction of hair include: LP ruby
(694 nm), LP alexandrite (755 nm), Pulsed
diode (800 nm), LP Nd:YAG (1064 nm)
lasers, IPL (590-1200 nm) sources. LP
Nd:YAG laser systems are more effective
particularly in patients with darker skin
phototypes.

The ORION. Vol 32, Issue 1, January 2009

Ablative laser systems
Cutaneous laser resurfacing has experienced
unparalleled growth in the field of aesthetic
operation during the past decade. High energy,
pulsed and scanned CO2 and erbium:YAG
lasers have been in widespread use since the
mid-1990s and the success of these lasers in
photodamaged facical skin has been well
documented.25 Because of flexibility and low
side effect profile, the high energy, pulsed and
scanned CO2 has been considered the gold
standard for facial rejuvenation system.
Nonablative laser systems
One of the newest trends in dermatology has
been the development of nonablative laser
systems. The infrared systems that have been
used for nonablative dermal remodeling
include: Nd:YAG laser (1320 and 1064 nm),
Diode laser (1450 nm), Er:glass laser (1540
nm).
Laser phototherapy
UV phototherapy has long been a mainstay in
the treatment of psoriasis. Recently, a 308-nm
xenon
chloride
excimer
laser
has
demonstrated clearing of psoriatic plaques
with fewer treatments than traditional narrowband UVB therapy. The laser only targets the
affected areas of the skin, thus sparing the
surrounding tissue from unnecessary radiation
exposure. The 308-nm excimer laser has also
been
used
to
treat
problems
of
dyspigmentation. In a pilot study, Spencer et
al demonstrated slight to complete
repigmentation in 57% of 23 patches of
vitiligo that received at least 6 treatments
during 2 to 4 weeks.26 These results are
encouraging
because
conventional
phototherapy often requires months of
treatment before improvement is seen. Acne
vulgaris is another cutaneous condition
amenable to phototherapy. Investigators have
reported a decrease in acne lesions after
exposure to blue, red, violet, or UV light. The
mechanism of action by which blue light is
thought to be effective is its absorption by
endogenous
porphyrins
produced
by
Propionibacterium acnes with subsequent
phototoxic effects.27 More recently, 1450 nm
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diode lasers have been used to target
sebaceous glands in the treatment of acne.30
Optical imaging
Diagnostic, noninvasive imaging is one of the
most exciting developments in laser
technology.
Confocal
scanning
laser
microscopy allows real-time imaging of tissue
in vivo and can provide rapid, high-resolution
imaging of skin cytology including the
epidermis, microvascular blood flow and
inflammatory cells.28 Potential clinical
applications include non invasive skin
imaging, detection of tumor margins and
diagnosis of lesions without biopsy.
Laser safety
Of paramount importance is the general safety
of both the patient and the operating room
personnel during laser irradiation. Key laser
safety issues include flammability, ocular
safety, electric hazards, laser plume and
infectious agents and controlled access to the
laser suite.
Anesthesia
Most dermatologic laser procedures can be
performed without any form of anesthesia.
The most commonly used topical anesthetic
compounds for cutaneous laser procedures are:
EMLA Cream (Lidocain 2.5% & Prilocain
2.5%), Ela-max Cream (Lidocain 2.5%)31, SCain Peel (Lidocain & Tetracain).
Side effects and complications
PDL treatment of port-wine stains,
hemangiomas, telangiectases, and vascular
ectasias typically result in a variable degree of
short-term purpura formation. Pigmented
lesions may lighten, darken, or recur after QS
laser irradiation. Transient pigmentary
alteration is the most common postoperative
side effect and may last for several months
after treatment. Complications of laserassisted hair removal using LP lasers are
usually minor and transient. The most
common adverse reactions include pain
during treatment, erythema and perifollicular
edema.

The ORION. Vol 32, Issue 1, January 2009

Conclusion
Although lasers capable of cutaneous
application have been available for more than
4 decades, it has been only within the past
several years that their use gained widespread
acceptance within the medical field. Lasers
have essentially revolutionized cosmetic
dermatology, providing safe and reliable
means for treating a variety of cutaneous
pathologies. With continued research and
development, it is expected that new
discoveries will continue to emerge leading to
significant treatment advances in laser surgery.
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